Basis for focus area |
Deposits near the Betts and Davis mines (see Hickmott and others, 1983; Slack and others, 1983; Quinn, 1945). |
Identified resources |
Historical production of manganese and pyrite. |
Production |
Mining intermittent from 1848-1943 (Hickmott and others, 1983). Past production estimated at 10,000 to 12,000 tons of ore which averaged 20-25% Mn (Quinn, 1945). Davis mine operated from 1882 to 1910; as of January 1, 1892 total production was 334,552 tons sulfide ore (pyrite, chalcopyrite) (Emerson, 1898b). |
Status |
Past mining. |
Estimated resources |
Unknown. |
Geologic maps |
Hatch (1969), scale 1:24,000; Osberg and others (1971), scale 1:24,000; Hatch and Hartshorn (1968), scale 1:24,000; Chidester and others (1967), scale 1:24,000. |
Geophysical data |
Inadequate aeromagnetic and aeroradiometric coverage. |
Favorable rocks and structures |
Stratabound manganese-rich zone within Ordovician metavolcanic and metasedimentary rocks of the Hawley Formation and in the underlying Moretown Formation (Hickmott and others, 1983). |
Deposits |
Betts manganese mine (MRDS dep_id: 10067329), Davis pyrite mines (MRDS dep_id: 10110223). |
Evidence from mineral occurrences |
MRDS; Mosier and others (2009); Stephens and others (1984). |
Geochemical evidence |
Whole rock geochemistry from samples and borings reported in Hickmott and others (1983) show anomalous amounts of Ag, As, Au, Ba, Co, Cu, Mo, Ni, P, Pb, Se, Sr, W, and Zn. |
Geophysical evidence |
Hickmott and others (1983, p. 68) there is a "strong correlation between elongate magnetic highs and the northeast trending regional schistosity, suggesting conformity of the ores to the surrounding metamorphosed strata" (see Scharon and others, 1945). |
Evidence from other sources |
Unknown. |
Comments |
All of the known manganese deposits are within a fine-grained graphitic mica schist facies of the Savoy schist. The two ore bodies of the Betts property appear to be on the noses of drag folds having vertical axes, and the manganese minerals appear to have replaced quartzite beds. The ores are chiefly manganese carbonates with lesser amounts of manganese silicates and with minor amounts of manganese oxides along the joints. Associated with the manganese minerals is an assemblage of sulfides, silicates, and oxides characteristic of high temperature hydrothermal deposits (Quinn, 1945). |
Cover thickness and description |
Variable limited cover and glacial cover estimated at less than 2-50 m. |
Authors |
Gregory J. Walsh, John F. Slack. |
New data needs |
Geochemistry, geophysics, mapping. |
Geologic mapping and modeling needs |
Mapping of deposits -- detailed traditional subsurface geologic mapping of structure and thickness using wireline logs and cores and potash grade using gamma ray logs and core geochemical analyses is needed. |
Geophysical survey and modeling needs |
High resolution aeromagnetic and aeroradiometric coverage. |
Digital elevation data needs |
Lidar complete. |